Application of ANN-PSO algorithm based on FDM numerical modelling for back analysis of EPB TBM tunneling parameters

2020 ◽  
pp. 1-18 ◽  
Author(s):  
Leila Nikakhtar ◽  
Shokrollah Zare ◽  
Hossein Mirzaei Nasirabad ◽  
Behnam Ferdosi
Keyword(s):  
Numerical Modelling ◽  
Back Analysis ◽  
Pso Algorithm ◽  
Epb Tbm

scholarly journals A Biological Immune Mechanism-Based Quantum PSO Algorithm and Its Application in Back Analysis for Seepage Parameters

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Jiacheng Tan ◽  
Liqun Xu ◽  
Kailai Zhang ◽  
Chao Yang
Keyword(s):  
Back Analysis ◽  
Computation Time ◽  
Vaccination Strategy ◽  
Pso Algorithm ◽  
Population Diversity ◽  
Local Optimum ◽  
Immune Mechanism ◽  
Convergence Performance ◽  
Poor Convergence ◽  
Quantum Pso

Back analysis for seepage parameters is a classic issue in hydraulic engineering seepage calculations. Considering the characteristics of inversion problems, including high dimensionality, numerous local optimal values, poor convergence performance, and excessive calculation time, a biological immune mechanism-based quantum particle swarm optimization (IQPSO) algorithm was proposed to solve the inversion problem. By introducing a concentration regulation strategy to improve the population diversity and a vaccination strategy to accelerate the convergence rate, the modified algorithm overcame the shortcomings of traditional PSO which can easily fall into a local optimum. Furthermore, a simple multicore parallel computation strategy was applied to reduce computation time. The effectiveness and practicability of IQPSO were evaluated by numerical experiments. In this paper, taking one concrete face rock-fill dam (CFRD) as a case, a back analysis for seepage parameters was accomplished by utilizing the proposed optimization algorithm and the steady seepage field of the dam was analysed by the finite element method (FEM). Compared with immune PSO and quantum PSO, the proposed algorithm had better global search ability, convergence performance, and calculation rate. The optimized back analysis could obtain the permeability coefficient of CFRD with high accuracy.

The influence of near face behaviour on monitoring of deep tunnels

1991 ◽  
Vol 28 (2) ◽  
pp. 226-238 ◽  
Author(s):  
F. Pelli ◽  
P. K. Kaiser ◽  
N. R. Morgenstern
Keyword(s):  
Numerical Modelling ◽  
Numerical Simulations ◽  
Three Dimensional ◽  
Back Analysis ◽  
Total Change ◽  
State Of Stress ◽  
Stress Changes ◽  
The Face ◽  
Tunnel Design

Convergence, radial displacements, and stress changes are often recorded during the advance of a tunnel for the observational tunnel design approach. In deep tunnels, instruments must be installed from underground and can seldom be placed in undisturbed ground. Consequently, observations are only partial records of the total change induced by an excavation and the influence of the three-dimensional state near the face must be considered. This paper presents results from numerical simulations to assess face effects on monitoring data. The influence of such aspects as in situ state of stress, anisotropy, nonlinearity, and plasticity (yielding ground) are evaluated. Guidelines for underground monitoring of deformations are given. Key words: tunnelling, monitoring, back-analysis, convergence, extensometers, numerical modelling.

scholarly journals Back analysis numerical modelling of the 19/06/1996 Cardoso (Stazzema, LU - Italy) flood: from gravitational movements to their evolution in rapid flows

2020 ◽  
Author(s):  
Michele Amaddii ◽  
Vincenzo D'Agostino ◽  
Leonardo Disperati ◽  
Pier Lorenzo Fantozzi
Keyword(s):  
Numerical Modelling ◽  
Back Analysis ◽  
Curve Number ◽  
Rheological Parameters ◽  
Drainage Network ◽  
Visual Interpretation ◽  
Discharge Data ◽  
Peak Intensity ◽  
Liquid Discharge ◽  
Flooded Area

<p>During the June 19th of 1996 a storm involved the Tyrrhenian sector of northern Tuscany (Italy), especially hitting the Versilia and Garfagnana areas. Major consequences and damages, due to the extremely intense precipitation (about 500 mm/13 h and 158 mm/h peak intensity), occurred in the surrounding of the Cardoso village (Versilia river basin, Stazzema, LU), with 14 casualties. At 1.20 p.m., the rainfall peak intensity coupled with the development of a large number of shallow landslides, triggered rapid flows and caused severe flooding in the Cardoso area, which was covered by hundred thousand of cubic meters of deposits.<br>The aim of this study was the characterization of the rapid flows occurred during the event and their back analysis numerical modelling by using a hydrological-hydraulic software. First of all, the amount of mobilized solid volume was assessed, differentiating between materials collapsed from the slopes and those eroded from the low-order drainage network. This goal was obtained by visual interpretation of post-event orthophotos and by morphometric analysis. Subsequently, starting from the rainfall data of the event, the hydrological modelling was performed by the Curve Number method, in order to define flood hydrographs along the drainage network of the Cardoso sub-basins. For the hydraulic modelling, the liquid discharge data were used to calculate debris-graphs of rapid flows, by implementing empirical correlations based on peak discharge, debris volume and channel slope. Different rheological parameters were tested to perform numerical modelling.<br>Back analysis results allow to infer that the mass movements initially started as hyperconcentrated flows in the upper parts of the sub-basins and after evolved into muddy debris flows, which caused flooding of the Cardoso valley. The results are in good agreement with the flooded area extent, as estimated by visual interpretation of both archive photos and aerial orthophotos acquired immediately after the event.</p>

Back analysis of the Joss Bay Chalk Cliff Failure using numerical modelling

2011 ◽  
Vol 120 (1-4) ◽  
pp. 81-90 ◽  
Author(s):  
T.D. Styles ◽  
J.S. Coggan ◽  
R.J. Pine
Keyword(s):  
Numerical Modelling ◽  
Back Analysis
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